Adding basic files

Adding basic files including meson build file, service files, git
config, clang-format and clang-tidy

Tested:
Buildable and service can up as expected.
```
bmc:~# busctl tree com.google.gbmc.boot_time_monitor
Only root object discovered.
```

Google-Bug-Id: 298918774
Change-Id: Ia88b00aa9bae1a4d04d5ec2a8dbe52f8c8bf8d2c
Signed-off-by: Michael Shen <gpgpgp@google.com>
11 files changed